Slope grader



R. F. BURTON Aug. 31, 1965 SLOPE GRADER 3 Sheets-Sheet 1 Filed May 17, 1963 INVENTOR.

Fofierf/FBurlaia MYW BY Ml ATTORNEYS 31, 1965 R. F. BURTON 3,203,120

SLOPE GRADER Filed May 17. 1963 5 Sheets-Sheet 2 I NVENTOR.

ATTORNEYS 1965 R. F. BURTON 3,203,120

- SLOPE GRADE-R Filed May 17, 1963 5 Sheets-Sheet 5 INVENTOR. 90627-2 F Earlon ATTORNEYS United States Patent 3,203,120 SLOPE GRADER Robert F. Burton, 3141 Wynn Drive, Avondale Estates, Ga. Filed May 17, 1963, Ser. No. 281,167 ll Claims. (Cl. 37-155) This invention relates to earth grading equipment and more particularly to a slope grader having a mold board which can be automatically and remotely positioned with its lower edge at a plurality of different angles to a horizontal plane and its face at a plurality of different angles to the surface being graded or sloped and without risk of damaging the slope grader.

The frequent requirement in road and other construction Work for grading road beds and for sloping ditches, shoulders, banks, and other slopes is generally met by attaching a slope grader to a conventional road grader. The slope grader is usually attached to the rear of the road grader so that the mold board of the slope grader extends to one side of the road grader. Means is customarily provided for pivoting the mold board in a horizontal plane about an axis and for pivoting the mold board in a vertical plane about an axis. The pivoting of the mold board in a horizontal plane provides the mold board with a horizontal component of motion which changes the effective length of the mold board. The pivoting of the mold board in a vertical plane provides the mold board with a vertical component of motion which permits the slope grader to grade slopes forming various angles with a horizontal plane.

However, various types of grading or sloping operations require different angles between the face of the mold board and the surface being graded or sloped. This means that in addition to its horizontal and vertical components of motion, as defined above, a mold board must rotate about a line coinciding with or parallel to its lengthwise axis. Thus, to be efficiently utilized for a variety of grading and sloping operations, a slope grader must have a mold board with horizontal and vertical components of pivotal motion and with a rotational component of motion.

Previous slope graders have been limited in that the rotational component of mold board motion has either been completely lacking or has been available only by manual adjustment of the mold board position. Where the rotational component of mold board motion is completely lacking, the angle between the face of the mold board and the surface being graded or sloped can not be adjusted to that angle necessary for certain grading or sloping operations and the usefulness of the slope grader is limited. Where the rotational component of mold board motion is variable only by manual adjustment, the usefulness of the slope grader is also limited because such manual adjustments are time consuming and annoying to the operator of the slope grader. Such manual adjustments are wholly impractical when the slope grader is being used to perform a grading or sloping operation or a series of grading or sloping operations requiring frequent changes in the position of the mold board along its vertical, horizontal and rotational components of motion.

The usefulness of previous slope graders for operations requiring frequent changes in mold board position has also been limited because previous slope graders have been characterized by excessive and dangerous torques, shearing forces, and other stresses under certain conditions of mold board motion. These stresses have resulted from the manner in which previous slope graders have joined the mold board of the slope grader to the leveling blade of the road grader to which the slope grader is attached.

3,25%,120 Patented Aug. 31, 1965 The present invention completely overcomes these dilficulties with and limitations of previous slope graders. It is a slope grader with a mold board having a wide range of movement along its vertical and horizontal components of pivotal motion and a rotational component of motion which without manual adjustment places the face of the mold board at the proper angle to the surface being graded or sloped. Moreover, these three compo nent-s of mold board motion are obtained without the eX- cessive and dangerous stresses and shearing forces which have characterized previous slope graders. The slope grader disclosed herein has a pivot assembly about which the mold board pivots to obtain all three components of mold board motion necessary for the slope grader to be used efficiently for grading or sloping operations requiring a plurality of mold board positions. No manual adjustments are necessary to obtain the proper rotational position of the mold board for each operation within a predetermined range of operations and the range of operations for which the mold board will be properly positioned is readily changed.

The slope grader disclosed herein utilizes a torque joint in a pull bar between the mold board of the slope grader and the leveling blade of the road grader which permits this efiicient and improved range of mold board motions without causing dangerous torques and other stresses which could damage the slope grader or the road grader with which it is used. Moreover, since manual adjustments of the mold board position are unnecessary during a particular grading operation or series of grading operations, the positioning of the mold board is completely under the remote control of the person operating the road grader. Thus, the invention provides a slope grader which can be efficiently used for a grading or sloping operation or a series of grading or sloping operations requiring a variety of mold board positions.

These and other features and advantages of the invention will be more clearly understood from the following detailed description and the accompanying drawings in which like characters of reference designate corresponding parts in all figures and in which:

FIG. 1 is a perspective view of a road grader with the slope grader attached.

FIG. 2 is a fragmentary rear elevational view of the mold board of the slope grader showing the pivot assembly when the mold board is horizontal and showing in dashed outline the cam bar and mold board when the mold board is pivoted and rotated.

FIG. 3 is a fragmentary cross sectional view of the mold board taken in line 33 in FIG. 2.

FIG. 4 is a cross sectional view of the mold board taken in line 44 in FIG. 2 and shows in solid outline the pivot assembly when the mold board is horizontal and in dashed outline the cam bar and mold board when the mold board is pivoted.

FIG. 5 is a perspective view of the pivot block used in the pivot assembly.

FIG. 6 is a fragmentary side elevational view of the pull bar showing the torque joint.

FIG. 7 is a top plan view of the torque joint removed from the bracket on the leveling blade.

FIG. 8 is a cross sectional view of the torque joint as seen in line 8-8 in FIG. 7.

FIG. 9 is a schematic presentation of the pivot assembly.

These figures and the following detailed description disclose a preferred specific embodiment of the invention, but the invention is not limited to the details disclosed since it may be embodied in other equivalent forms.

This invention is best understood as an attachment to a conventional road grader 20. Such a conventional road grader generally has a wheeled frame 21 above which the motor 22 and the person operating the road grader are positioned and below which a leveling blade 23 is positioned. The leveling blade 23 is suspended between the ground and the frame 21 by attaching it in known manner to a ring 24 mounted on the under side of the frame 21. The ring 24 is rotated by power in known manner and its rotation positions the leveling blade 23 at various angles in a horizontal plane with respect to the direction of travel of the road grader 20.

The slope grader is attached to a conventional road grader 20 by extending two bracket plates 25 and 26 from the rear 28 of the frame 21 of the road grader 20. These bracket plates 25 and 26 extend between the frame of the road grader 20 and a horizontal cylinder 27. The horizontal cylinder 27 is open at both ends and is fixedly positioned adjacent to the rear 28 of the road grader 20 with its center line in a horizontal plane and perpendicular to the direction of travel of the road grader 20. An outer extension cylinder 29 has one end slidably inserted into the open right end 31 of the horizontal cylinder 27 and its other end integral with a vertical cylinder 30.

The outer extensional cylinder 29 can be completely removed from the horizontal cylinder 27 or it can be manually placed in either of two fixed positions. In one fixed position, the outer extension cylinder 29 is rotated and slid within the horizontal cylinder 27 so that the center line of the vertical cylinder 30 is substantially perpendicular to a horizontal plane and relatively remote from the right end 31 of the horizontal cylinder 27. In its second position, the outer extension cylinder 29 is slid into the horizontal cylinder 27 and rotated within the horizontal cylinder 27 so as to place the vertical cylinder 30 adjacent to the right end 31 of the horizontal cylinder 27 and with the center line of the vertical cylinder 30 in a horizontal plane. The first position is to place the slope grader in operating position and the second position is to place the slope grader in transporting position. The outer extension cylinder 29 is manually moved between these two fixed positions and is locked in either fixed position by extending a bolt 32 in known manner through one of a plurality of appropriately placed holes (not shown) in the horizontal cylinder 27 and one of a plurality of appropriately placed holes (not shown) in the outer extension cylinder 29.

The upper end of the vertical cylinder 33 is closed and a heel cylinder 33 is slidably inserted into the lower end of the vertical cylinder 30. The heel cylinder 33 has a heel 34 at its lower end. The heel 34 is part of the pivot assembly to be described and the inner end 35 of the mold board 36 is associated with the pivot assembly so as to permit that pivotal motion and control that rotational motion of the mold board 36 requires for effective utilization of the mold board 36. The vertical cylinder 30 has a cap 37 rotatably positioned on its upper end and an extension bar 38 extending between a bracket 39 on the cap 37 and a bracket 40 positioned on the back 49 of the mold board 36 substantially midway between the inner end 35 and the outer end 41 of the mold board 36.

The extension bar 38 comprises a cylindrical segment 42 having a closed end pivotally attached to the bracket 39 and an open end from which a piston segment 43 slidably extends. The extending end of the piston segment 43 is attached to the bracket 40 through a universal joint 44 of known type. As the extension bar 33 shortens with movement of the piston segment 43 into the cylindrical segment 42, the outer end 41 of the mold board 36 pivots upward about the pivot assembly and as the extension bar 38 lengthens with the movement of the piston segment 43 out of the cylindrical segment 42, the outer end 41 of the mold board 36 pivots downward about the pivot assembly.

A substantially rigid pull bar 45 extends between the leveling blade 23 of the road grader 2t) and the mold board 36 of the slope grader. This pull bar 45 comprises a vertical component 46 attached at its lower end through a universal joint 47 of known type to a bracket on the back 43 of the mold board 36, adjacent to the bracket 40, a hollow cylindrical component 50 having an open end and a closed end fixedly attached to the upper end of the vertical component 46, and a rod component 51 having one end slidably inserted into the open end of the cylindrical component 50 and its other end attached to a bracket 52 on the back of the leveling blade 23 through the torque joint to be described. The cylindrical component 50 has a hole (not shown) through it adjacent to its open end and the rod component Sll has a plurality of holes 99 spaced along its length and the length of the pull bar 45 is adjusted by inserting a shear pin 53 through the hole in the cylindrical component 50 and through one of the plurality of holes 99 in the rod component 51.

The length of the pull bar 45 is adjusted to place the mold board 36 in a particular general position with reference to the leveling blade 23 of the road grader 20. The mold board 36 is provided with a horizontal component of motion with reference to this general position by moving the leveling blade 23 in known manner. Pivotal motion of the leveling blade 23 will impart pivotal motion in a horizontal plane to the mold board 36 about the pivot assembly to be described.

A road grader generally has a source of hydraulic pressure (not shown) and the extension bar 38 and the vertical cylinder 33 and heel cylinder 33 are constructed in known manner so that this source of hydraulic pressure is used to raise and lower the heel cylinder 33 in the vertical cylinder 30 and to shorten and lengthen the extension bar 38. This is achieved by extending hydraulic lines 55 of known type and in known manner between the source of hydraulic pressure and the vertical cylinder 30 and between the source of hydraulic pressure and the extension bar 38. The application of hydraulic pressure to the vertical cylinder 33 and to the extension bar 38 is controlled in known manner from the operator station 54 of the road grader 20. The position of the leveling blade 23 of the road grader 20 is also controlled from the operator station 54 in known manner.

Thus, the position of the slope grader and of its mold board 36 is adjustable with reference to the road grader 25 by manually changing the slidable position of the outer extension cylinder 29 within the horizontal cylinder 27, by slidably moving the heel cylinder 33 within the vertical cylinder 30 with hydraulic pressure, by shortening and lengthening the extension bar 38 with hydraulic pressure, and by moving the leveling blade 23 of the road grader 20 in known manner. It is the shortening and lengthening of the extension bar 38 and the motion of the leveling blade 23 which provide the mold board 36 of the slope grader with the horizontal and vertical components of pivotal motion required during a grading or sloping operation or during a series of grading or sloping operations.

The manner in which the shortening and lengthening of the extension bar 38 and the motion of the leveling blade 23 provide the necesary horizontal and vertical components of pivotal motion to the mold board 36 has already been described. However it is the pivot assembly and a torque joint in the pull bar 45 which permit this pivotal motion. Moreover, it is the pivot assembly which controls the rotation motion of the mold board 36 required to maintain the proper angle between the face 69 of the mold board 36 and the surface being graded or sloped.

The pivot assembly comprises the heel 34, a left pivot plate 56, a right pivot plate 57, and a cam bar 58. The left pivot plate 56 and right pivot plate 57 are fixedly attached to the back 49 of the mold board .5 36. The left pivot plate 56 and right pivot plate 57 extend from the back 49 of the mold board 36 toward each other and at its extending end the left pivot plate 56 is formed into a left pivot surface 59 perpendicular to the back 49 of the mold board 36. Similiarly, at its extending end, the right pivot plate 57 is formed into a right pivot surface 66 perpendicular to the back 49 of the mold 36.

A lower pivot bolt 61 extends between the left pivot surface 59 and the right pivot surface 60. The lower pivot bolt 61 is fixedly positioned between the left pivot surface 59 and the right pivot surface 60 parallel and adjacent to the lower edge 62 of the mold board 36. A pivot block 63 is rotatably positioned on the lower pivot bolt 61 between the left pivot surface 59 and the right pivot surface 60 by extending the lower pivot bolt 61 through a lower passage 66 in the pivot block 63. The pivot block 63 also has an upper passage 65 extending through it with the axis of the upper passage 65 being above and perpendicular to the axis of the lower passage 64 through the pivot block 63.

The heel 34 is pivotally attached to the pivot block 63 by inserting an upper pivot bolt 66 through the upper passage 65 and through a front tab 67 and a back tab 68 fixedly attached to and extending below the heel 34. The pivot block 63 is between the front tab 67 and the back tab 68 and will pivot about the upper pivot bolt 66.

As a result of this arrangement, the pivot block 63, the lower pivot bolt 61, the left pivot plate 56, the right pivot plate 57, and the mold board 36 will pivot in a vertical plane about the upper pivot bolt 66, and the left pivot plate 56, the right pivot plate 57 and the mold board 36 will pivot in a plane perpendicular to this vertical plane about the lower pivot bolt 61. The heel cylinder 33 rotates in the vertical cylinder 30 and as a result the pivot block 63, the upper pivot bolt 66, the lower pivot bolt 61, the left pivot plate 56, the right pivot plate 57, and the mold board 36 will all pivot in a horizontal plane with the heel cylinder 33.

The pivot assembly efliciency accommodates the vertical component of mold board 36 pivotal motion by permitting the mold board 36 to pivot about the upper pivot bolt 66 as the outer end 41 of the mold board 36 is raised or lowered by the extension bar 38 as already described. A wide range of such pivotal motion of the mold board 36 is insured by swedging the heel 34 inward toward the front tab 67 and the rear tab 63 and by sloping the uper edge of the left pivot plate 56 and upper edge of the right pivot plate 57 downward as well as inward from the back 49 of the mold board 36 toward the pivot block 63. Thus the outer end 41 of the mold board 36 may pivot upward or downward about the upper pivot bolt 66 to a significant degree before either the left pivot plate 56 or the right pivot plate 57 will engage the heel cylinder 33 on the heel 34.

The pivot assembly efficiently accommodates the horizontal component of mold board 36 motion by permitting the mold board 36 to pivot with the heel cylinder 34 as the leveling blade 23 changes position and moves the outer end 41 of the mold board 36 as already described. The motion of the mold board 36 about the lower pivot bolt 61 is the rotational motion which provides the changing angle between the face 6? of the mold board 36 and the surface being graded. This motion is about an axis through the lower pivot bolt 61 and parallel to the lengthwise axis of the mold board 36 and is controlled by a positioning member which, in this embodiment, is the cam bar 58 of the pivot assembly.

The cam bar 58 is a crescent shaped bar having two parallel tabs 76 at its left end and two parallel tabs 71 at its right end. A left ear 72 extends from the back 49 of the mold board 36 and the left end of the cam bar 58 is pivotally attached to the left ear 72 by placing the left ear 72 between the tabs 70 and extending a pin 73 in known manner through the tabs 70 and the left ear 72. A right car 74 also extends from the back 49 of the mold board 36 and the right end of the cam bar 53 is pivotally attached to the right ear 74 by inserting the right ear 74 between the tabs 71 and extending a pin 75 in known manner through the tabs 71 and the right ear 74.

The heel cylinder 33 is between the back 49 of the mold board 36 and the cam bar 58 as the cam bar 58 extends between the left ear 72 and the right ear 74. Thus, when the back 49 of the mold board 36 is viewed as in FIG. 2, the left ear 72 and the left end of the cam bar 58 are to the left of the heel cylinder 33 and the right ear 74 and the right end of the cam bar 58 are to the right of the heel cylinder 33.

The cam bar 58 is slidably associated with the heel cylinder 33 by passing the cam bar 58 through a passage bounded by a bearing plate 77 fixedly attached to the heel cylinder 33, a clamp plate 78 parallel to the bearing plate 77 and two clamp bolts 79 extending through the bearing plate 77 and the clamp plate 78 into the heel cylinder 33. Although the cam bar 58 slides freely in the passage formed by the bearing plate 77, the clamp plate 78 and the clamp bolts 79, the passing of the cam bar 58 through this passage serves to fix the location of a point along the length of the cam bar 58. It is the fixing of a point along the length of the cam bar 58 in this manner, the locations of the left ear 72 and the right car 74, and the configuration of the cam bar 58 which control the rotational motion of the mold board 36 about a line parallel to the lengthwise axis of the mold board 36 and coinciding with the axis of the lower pivot bolt 61.

The fixing of the cam bar 58 by the passage formed by the clamping means above described aids in the control of the mold board by causing a change in the effective length of the cam bar 58. The cam bar 58, as previously mentioned, is curved so that the perpendicular distances from the mold board to various points along the cam bar vary; therefore, as different points along the cam bar 58 bear against the bearing plate 7'7, the perpendicular distance from the bearing plate 77 to the mold board will vary.

The clamping means is used primarily to prevent the cam bar 58 from pivoting downwardly by gravity and engaging a lower portion of the heel 34, giving inaccurate positioning of the mold board due to change in dimensions of the heel 34; however, with the fixing of the vertical position of the cam bar 58 on the heel 34, as the mold board is rotated in a vertical plane, the cam bar 58 will be slanted, as shown in FIG. 4 of the drawings. Since in this slanted position, the perpendicular distance from the bearing plate 77 to the mold board 36 is less than the distance from that portion of the cam bar that is against the bearing plate 77 to the pins 73 and '75 of the cam bar 58, this slanting of the cam bar must be considered in figuring the position of the mold board 36.

Although the rotational motion of the mold board 36 will vary from one embodiment of the invention to another, the nature of the motion is well illustrated by the embodiment of the invention shown in FIGURES 2, 3 and 4. With this embodiment of the invention, the upper edge 86 and lower edge 62 of the mold board 36 are in a substantially vertical plane when the lower edge 62 is horizontal and in a plane tilting forward in the direction of road grader 20 travel when the lower edge 62 of the mold board 36 forms an angle with a horizontal plane. Thus, this embodiment of the invention provides the proper angle to the face 69 of the mold board 36 for grading when the mold board 36 is horizontal and the proper angle for smoothing sloping surfaces when the outer end 41 of the mold board 36 is 7 pivoted upward or downward about the upper pivot bolt 66.

The left ear 72 and right ear 74 are positioned on the back 49 of the mold board 36 so that a line 81 coinciding with and joining the center lines of the pins 73 and 75 is parallel to the center line of the lower pivot bolt 61 and between a horizontal plane through the lower pivot bolt 61 and a horizontal plane through the middle of the bearing plate 77. This line 81 will rotate about the lower pivot bolt 61 as the mold board 36 rotates about the lower pivot bolt 61 and the position of the line 81 determines the rotational position of the mold board 36. When the lower edge 62 of the mold board 36 is horizontal, the line 81 is horizontal and the cam bar 53 slopes downward from the bearing plate 77 to the pin 73 where its left end is pivotally attached and to the pin 75 where its right end is pivotally attached.

The shape of the cam bar 58 is selected so that when the lower edge 62 of the mold board 36 is horizontal, the midpoint of the cam bar 58 is between the bearing plate 77 and the clamp plate 78 and the left side of the cam bar 58 curves toward the mold board 36 and downward from the midpoint to the pin 73 and the right side curves in similar fashion from the midpoint to the pin 75. With the cam bar 58 in this position, the upper edge 80 and lower edge 62 of the mold board 36 are in the same substantially vertical plane.

This substantially vertical position of the face 69 of the mold board 36 is for convenience of explanation defined by the length of a reference line 82 extending between the midpoint of the bearing plate 77 and a reference plane 83 containing the line 81 between the pins 73 and '74. The reference plane 83 is vertical and parallel to the center line of the lower pivot bolt 61 and the reference line 82 is parallel to the center line of the upper pivot bolt 66 and perpendicular to the center line of the lower pivot bolt 61. If the reference line 82 is shortened, the reference plane 83, the line 81 between the pins 73 and 74, and the upper edge 80 of the mold board 36 move toward the heel cylinder 33 so as to tilt the face 69 of the mold board 36 backward. On the other hand, if the reference line 82 is lengthened, the reference plane 83, the line 81 between pins '73 and 74, and the upper edge 80 of the mold board 36 move away from the heel cylinder 33 so as to tilt the face 69 of the mold board 36 forward.

The length of the reference line 82 is less than the length of a line 84 extending from the midpoint of the bearing plate 77 to and perpendicular to the line 81 between the pins 73 and 75 because the cam bar 58 slopes downward from the bearing plate 77 when the lower edge 62 of the mold board 36 is horizontal. However, the

length of this reference line 82 will remain fixed as long h as the lower edge 62 of the mold board 36 is horizontal because the positioning of the midpoint of the cam bar 58 between the bearing plate 77 and clamp plate 78 will prevent rotation of the mold board 36 about the lower pivot bolt 61. Thus, the face 69 of the mold board 36 is firmly fixed in the desired position for operations requiring the mold board 36 to be horizontal.

When the mold board 36 is pivoted about the upper pivot bolt 66 into a postion in which the lower edge 62 of the mold board 36 forms an angle with a horizontal plane, the bearing plate 77 remains stationary and the left ear 72 or right ear 76 moves upward while the other ear 72 or 74 moves downward. Since the upper pivot bolt 66 is below the bearing plate 77, this pivoting of the mold board 36 causes the cam bar 58 to pivot and slide between the bearing plate 77 and clamp plate 7 8 to the extent necessary to accommodate the horizontal and vertical components of left ear 72 and right ear 74 motion. The pivotal attaching of the cam bar 58 to the ears 73 and 74 permits the cam bar 58 to pivot about the line 81 between pins 73 and 75 to the extent necessary for this cam bar 53 motion between the bearing plate 77 and clamp plate 78.

After the mold board 36 has been pivoted so that its lower edge 62 is no longer horizontal, the line 81 between the pins 73 and 75 is the line 81a and is tilted in the reference plane 83 so that it intersects or nearly intersects the reference line 82. This means that reference line 32 now coincides with or nearly coincides with the line 84a extending from the midpoint o fthe bearing plate 77 to and perpendicular to the line 81a between the pins 73 and 75. The line 84a is the new position of the line 84 and when the lower edge 62 of the mold board 36 was horizontal, the line 84 was longer than the reference line 32 because the line 84- and the cam bar 58 extended downward. Thus, the pivoting of the cam bar 58 and the tilting of the line 81 between the pins 73 and 75 has the tendency to lengthen the reference line 82 to the length of line 84 and to tilt the face 69 of the mold board 36 forward away from the heel cylinder 33.

However, when the lower edge 62 of the mold board 36 is horizontal, the length of the line 84 is the distance from the midpoint of the cam bar 58 to and perpendicular to the line 81. After pivoting of the mold board 36 and sliding of the cam bar 58 between the bearing plate 77 and clamp plate 78, the length of the line 84a is no longer the length of line 84. This is because the cam bar 58 curves toward the line 81 on both sides of its midpoint and the sliding of the cam bar 58 between the bearing plate 77 and clamp plate 78 places a segment of the cam bar 58 between the bearing plate 77 and the clamp plate 78 which is less distance from the line 81 than the midpoint of the cam bar 58. Thus, as the mold board 36 pivots about the upper pivot bolt 66, the line 84 decreases in length as it becomes line 84a.

The result of this change in the length of the line 54 with pivoting of the mold board 36 is that the pivotal length of the reference line 82 is not the length of the line 64 when the lower edge 62 of the mold board 36 is horizontal, but rather is some lesser length defined by line 84a and depending upon the configuration of the cam bar 58 and the position of the cam bar 58 between the bearing plate 77 and clamp plate 78. In the embodiment of the invention described herein, the length of the line 84 and the configuration of the cam bar 58 are empirically selected so that the line 84a is just sutficiently longer than the original length of the reference line 82 to pivot the face 69 of the mold board 36 forward by a particular desired amount as the mold board 36 pivots and the line 84 becomes line 64a and moves to coincide with the reference line 82.

The embodiment of the invention described herein provides a mold board 36 having a face 69 which is sub stantially vertical when the mold board 36 is horizontal and which tilts forward when the mold board 36 is pivoted. Other responses of the mold board 36 with pivoting of the mold board 36 are possible with proper selecting of cam bar 58 configuration and the location of the cars 72 and '74. For example, if the cars 72 and 74 are positioned on the back 49 of the mold board 36 so that the line 84 and reference line 82 coincide when the lower edge 62 of the mold board 36 is horizontal, pivoting of the mold board 36 will cause only shortening of the reference line 82 and tilting of the face 69 of the mold board toward the heel cylinder 33. Similarly, regardless of the locations of the ears 72 and 74, changing the configuration of the cam bar 58 will change the rotational motion of the mold board 36 as it pivots about the lower pivot bolt 61.

Thus, the pivot assembly permits pivotal motion of the mold board 36 and depending upon the locations of the ears 72 and 741 and the cam bar 58 configuration, the pivot assembly provides a range of mold board 36 rotational motion which can be changed by simply changing the cam bar 53. It is the torque joint which permits this pivotal and rotational motion of the mold board 36 without excessive shearing forces and other stresses.

The torque joint is in the pull bar 45. A connector block 85 is pivotally mounted between the horizontal tabs 86 and 87 of the bracket 52. on the back of the leveling blade 23 of the road grader 20 by extending a vertical pin 38 through the tabs 86 and 87 and through a vertical passage 89 in the connector block 85. A horizontal passage 90 extends through the connector block 85 more remote from the bracket 52 than the vertical passage 8%. A left connector tab 91 and a right connector tab 92 are jointed to the connector block 85 by extending a horizontal pin 93 in known manner through the left connector tab 91, the right connector tab 92, and the horizontal passage 99 of the connector block 85.

A torque ring 94 is fixedly positioned between the left connector tab 91 and the right connector tab 92 with its center line perpendicular to the center line of the horizontal pin 93. The torque ring 94 pivots in a vertical plane about the horizontal pin 93; and, with the connector block 85, the torque ring 94 pivots in a horizontal plane about the vertical pin 88.

The rod portion 51 of the pull bar 4 is slidably inserted through the torque ring 94 and a torque limiting ring 95 is fixedly attached to the end of the rod portion 51 between the connector block 85 and the torque ring 94. A positioning ring 96 is fixedly positioned on the rod portion 51 of the pull bar 45 on the opposite side of the torque ring 94 from the torque limiting ring 95. The outside diameters of both the torque limiting ring 95 and the positioning ring 96 are greater than the inside diameter of the torque ring 94 and as a result, the torque limiting ring 95 and the positioning ring )6 serve to limit the slidable motion of the rod portion 51 of the pull bar 45 within the torque ring 94. However, the rod portion 51 of the pull bar 45 is rotatable within the torque ring 94.

This arrangement of the torque joint permits the pull bar 45 joining the leveling blade 23 and the mold board 36 to pivot and to twist or rotate as the mold board 36 and leveling blade 23 change positions with respect to each other. It eliminates those shearing forces involving both a component along the length of the pull bar 45 and a component perpendicular to the length of the pull bar 45 which tend to shear the bolt 53 in the pull bar 45.

The vertical component 46 of the pull bar 45 is attached to the back of the mold board 36 through a universal joint 47 of known type and this universal joint 47 and the rotational motion of the rod component 51 within the torque ring 94 provide no means for maintaining the vertical component 45 of the pull bar 45 in a substantially vertical position. This is provided for by an upper stop 97 and a lower stop 95 extending from the torque limiting ring 95. When the vertical component 46 is substantially vertical, the upper stop 97 extends upward from the torque limiting ring 95 between the left connector tab 51 and the right connector tab 92 and the lower stop extends downward between the left connector tab 91 and the right connector tab 92.

As the rod component 51 rotates within the torque ring $4, the upper stop 97 and lower stop 98 engage the left connector tab 91 and right connector tab 9?. and prevent further rotation of the rod component 51 within the torque ring 94. The width of the stops 97 and 98 is selected to permit that rotation of the rod component 51 necessary to prevent shearing forces and other stresses as the mold board 36 moves within a desired range of pivotal and rotational motion and to check that addition rotational motion of the rod component 51 which would cause the vertical member 46 to be not substantially vertical.

It will be obvious that many variations may be made in the embodiment here chosen for the purpose of illustrating the present invention without departing from the scope thereof as defined by the appended claims.

What is claimed as my invention is:

frame, a heel cylinder carried by said frame, a mold board pivotally carried by said heel cylinder, a left, ear fixedly attached to the back of the mold board between the inner end of the mold board and a plane through the heel cylinder perpendicular to the back of the mold board, said left ear being perpendicular to said mold board; a right ear fixedly attached to the backof the mold board on the opposite side of the said plane through the heel cylinder from the left ear said right ear being perpendicular to said mold board; a cam bar having a left end adjacent to the left ear, a right end adjacent to the right ear, a mid portion adjacent to the heel cylinder but more remote from the mold board than the heel cylinder, a left portion between its mid portion and its left end which curves toward the mold board from the mid portion, and a right portion between its mid portion and its right end which curves toward the mold board from the mid portion; a right pin extending through the right ear and the right end of the cam bar, said right end of the cam bar being pivotable about the centerline of the right pin; a left pin extending through the left ear and the left end of the cam bar with its centerline coinciding with the centerline of the right pin, said left end of the cam bar being pivotable about the centerline of the left pin; a bearing plate fixedly attached to the heel cylinder between the heel cylinder and the mid portion of the cam bar; a clamp plate positioned adjacent to the mid portion of the cam bar but more remote from the heel cylinder than the cam bar; an upper bolt fixedly extending through the clamp plate and the bearing plate above the mid portion of the cam bar; a lower bolt fixedly extending through the clamp plate and the bearing plate below the mid portion of the cam bar.

2. A slope grader for use with a road grader having a frame, said slope grader, comprising, in combination, two positioning brackets attachable to the rear of a frame of the road grader; a horizontal cylinder fixedly attached to the positioning brackets; an outer extension cylinder within the horizontal cylinder; a vertical cylinder fixedly attached to the extending end of the outer extension cylinder; a heel cylinder with a lower end and with its upper end rotatably inserted into the vertical cylinder; a heel integral with the lower end of the heel cylinder; a mold board having a back, an inner end to be positioned adjacent a road grader, and an outer end to be positioned remote from a road grader; a left pivot plate fixedly attached to the back of the mold board; a right pivot plate fixedly attached to the back of the mold board; a pivot block positioned between the left pivot plate and the right pivot plate and having a lower passage through it and an upper passage through it perpendicular to its lower passage; a lower pivot bolt extending between the left pivot plate and the right pivot plate through the lower passage of the pivot block, said pivot bolt being freely rotatable within said lower passage; a front tab extending from the lower end of the heel between the pivot block and the back of the mold board; a back tab extending from the lower end of the heel and on the opposite side of the pivot block from the front tab; an upper pivot bolt extending between the front tab and the back tab through the upper passage of the pivot block, said pivot block being rotatable about the said upper pivot bolt; a cam bar having a left end and a right end attached to the back of the mold board and pivotable about a line parallel to the lower pivot bolt and having a first segment adjacent to the heel cylinder but more remote from the mold board than the heel cylinder, a second segment between its first segment and left end which curves toward the mold board from the first segment, and a third segment between its first segment and its right end which curves toward the mold board from the first segment; a bearing plate fixedly attached to the heel cylinder between the cylindrical cylinder and the first segment of the cam bar; a clamp plate positioned adjacent to the first segment of the cam bar but more remote from the heel cylinder than the cam bar; bolts fixedly extending through the clamp plate and the bearing plate above and below the first segment of the cam bar; means for rotating theheel cylinder within the vertical cylinder; and means for pivoting the pivot block about the upper pivot bolt.

3. A slope grader for use with a road grader, said slope grader, comprising, in combination, a vertical cylinder attachable to the frame of a road grader; a heel cylinder rotatable within the vertical cylinder about a vertical axis; a heel integral with the lower end of the heel cylinder; a mold board having a lower edge; means attaching the mold board to the heel permitting rotation with the heel cylinder, permitting pivotal motion in a vertical plane, and permitting pivotal motion about a line parallel to the lower edge of the mold board; a clamping means mounted on the heel cylinder; a cam bar having its ends pivotally attached to the mold board, said cam bar being pivotal about a line between its ends and parallel to the lower edge of the mold board and having a segment between its ends slidably connected with the clamping means; means for pivoting the mold board in a horizontal plane and a vertical plane of motion.

4. A slope grader for use with a road grader having a frame, a vertical cylinder carried by said frame, a heel cylinder slidable within said vertical cylinder, a mold board pivotably carried by said heel cylinder, a leveling blade carried by said frame at a point removed from said heel cylinder, said leveling blade being movable with respect to said frame; a left ear fixedly attached to the back of the mold boar-d between the inner end of the mold board and a plane through the heel cylinder perpendicular to the back of the mold board; a right ear fixedly attached to the back of the mold board on the opposite side of the said plane through the heel cylinder from the left ear; a cam bar having a left end adjacent to the left car, a right end adjacent to the right car, a first segment adjacent to the heel cylinder but more remote from the mold board than the heel cylinder, a second segment between its first segment and left end which curves toward the mold board, and a third segment between its first segment and its right end which curves toward the mold board; a right pin fixedly insorted through the right ear and the right end of the cam bar, said right end of the cam bar being pivotable about the centerline of the right pin; a left pin fixedly inserted through the left ear and the left end of the cam bar, said left end of the cam bar being pivotable about the centerline of the left pin and said left pin having its centerline coinciding with the centerline of the right pin; a bearing plate fixedly attached to the heel cylinder between the heel cylinder and the cam bar; a clamp plate positioned adjacent to the cam bar; an upper bolt fixedly extending through the clamp plate and the bearing plate above the cam bar; a lower bolt fixedly extending through the clamp plate and the bearing plate below the cam bar; an extension bar pivotally and rotatably attached to the upper end of the vertical cylinder and pivotally attached to the outer end of the mold board, said extension bar having means for changing its length; a leveling blade bracket mounted on the leveling blade of the road grader; two horizontal tabs spaced apart and extending from the leveling blade bracket toward the mold board; a connector block between the horizontal tabs, said connector block having a vertical passage through it and a horizontal passage through it more remote from the leveling blade than the vertical passage; a vertical pin extending through the horizontal tabs and the vertical passage of the connector block, said connector block being rotatable about the vertical pin; a horizontal pin inserted through the horizontal passage of the connector block; a left connector tab pivotally attached to one extending end of the horizontal pin; a right connector tab pivotally attached to the other extending end of the horizontal pin; a torque ring fixedly positioned between the left connector tab and the right connector tab with its centerline perpendicular to the centerline of the vertical pin; a vertical member having an upper end and its lower end pivotally attached to the back of the mold board; a rod having one end attached to the upper end of the vertical member and its other end slidably and rotatably inserted through the torque ring; a positioning ring fixedly on the rod between the vertical member and the torque ring, said positioning ring being adjacent to the torque ring and being too large to pass through the torque ring; a torque limiting ring fixedly on the rod between the left connector tab and right connector tab, said torque limiting ring being too large to pass through the torque ring; and stops extending from the torque limiting ring between the left connector tab and the right connector tab.

5. A slope grader for use with a road grader having a frame, a heel cylinder carried by said frame, a mold board pivotably carried by said heel cylinder, a leveling blade carried by said frame at a point removed from said heel cylinder, said leveling blade being movable with respect to said frame; a left ear fixedly attached to the back of the mold board between the inner end of the mold board and a plane through the heel cylinder perpendicular to the back of the mold board; a right ear fixedly attached to the back of the mold board on the opposite side of the said plane through the heel cylinder from the left car; a cam bar having a left end adjacent to the left ear, a right end adjacent to the right ear, a first segment adjacent to the heel cylinder but more remote from the mold board than the heel cylinder, a second segment between its first segment and its left end which curves toward the mold board, and a third segment between its first segment and its right end which curves toward the mold board; a right pin fixedly inserted through the right ear and the right end of the cam bar, said right end of the cam bar being pivotable about the centerline of the right pin; a left pin fixedly inserted through the left ear and the left end of the cam bar, said left end of the cam bar being pivotal about the centerline of the left pin and said left pin having its centerline coinciding with the centerline of the right pin; a bearing plate fixedly attached to the heel cylinder between the heel cylinder and the cam bar; a clamp plate positioned adjacent to the cam bar; an upper bolt fixedly extending through the clamp plate and the bearing plate above the cam bar; a lower bolt fixedly extending through the clamp plate and the bearing plate below the cam bar; a leveling blade bracket mounted on the leveling blade of the road grader; two horizontal tabs spaced apart and extending from the leveling blade bracket toward the mold board; a connector block between the horizontal tabs, said connector block having a vertical passage through it and a horizontal passage through it more remote from the leveling blade than the vertical passage; a vertical pin extending through the horizontal tabs and the vertical passage of the connector block, said connector block being rotatable about the vertical pin; a horizontal pin inserted through the horizontal passage of the connector block; a left connector tab pivotally attached to one extending end of the horizontal pin; a right connector tab pivotally attached to the other extending end of the horizontal pin; a torque ring fixedly positioned between the left connector tab and the right connector tab with its centerline perpendicular to the centerline of the vertical pin; a vertical member having an upper end and its lower end pivotally attached to the mold board; a rod having one end attached to the upper end of the vertical member and its other end slidably and rotatably inserted through the torque ring; a positioning ring fixedly on the rod between the vertical member and the torque ring, said positioning ring being adjacent to the torque ring and being too large to pass through the torque ring; a

13 torque limiting ring fixedly on the rod between the left connector tab and right connector tab, said torque limiting ring being too large to pass through the torque ring; stops extending from the torque limiting ring between the left connector tab and the right connector tab; and means for pivoting the mold board in a vertical plane.

6. A slope grader for use with a road grader having a pivotally movable leveling blade, said slope grader, comprising, in combination, a mold board having a lengthwise axis; means for mounting the mold board on the slope grader for pivotal motion of its said lengthwise axis in horizontal and vertical planes; means for pivoting the mold board so that its lengthwise axis moves in a vertical plane; a leveling blade bracket mountable on the leveling blade of a road grader; two horizontal tabs spaced apart and extending from the leveling blade bracket toward the mold board; a connector block between the horizontal tabs, said connector block having a vertical passage through it and a horizontal passage through it more remote from the leveling blade bracket than the vertical passage; a vertical pin extending through the horizontal tabs and the vertical passage of the connector block, said connector block being rotatable about the vertical pin; a horizontal pin inserted through the horizontal passage of the connector block; a left connector tab pivotally at tached to one extending end of the horizontal pin; a right connector tab pivotally attached to the other exending end of the horizontal pin; a torque ring fixedly positioned between the left connector tab and the right connector tab with its centerline perpendicular to the centerline of the vertical pin; a vertical member having an upper end and its lower end pivotally attached to the mold board; a rod having one end attached to the upper end of the vertical member and its other end slidably and rotatably inserted through the torque ring; a positioning ring on the rod between the vertical member and the torque ring, said positioning ring being adjacent to the torquering and being too large to pass through the torque ring; a torque limiting ring on the rod between the left connector tab and right connector tab, said torque limiting ring being too large to pass through the torque ring; and stops extending from the torque limiting ring between the left connector tab and the right connector tab and engaging the left connector tab and the right connector tab if the vertical member is not substantially vertical.

7. A slope grader for use with a road grader having a pivotally movable leveling blade, said slope grader, comprising, in combination, a mold board having a lengthwise axis; means for mounting the mold board on a slope grader for pivotal motion of its said lengthwise axis in horizontal .and vertical planes; means for pivoting the mold board so that its lengthwise axis moves in a vertical plane; a leveling blade bracket mountable on the leveling blade of a road grader; two horizontal tabs spaced apart and extending from the leveling blade bracket toward the mold board; a connector block between the horizont-al tabs, said connector block having a vertical passage through it and a horizontal passage through it more remote from the leveling blade bracket than the vertical passage; a vertical pin extending through the horizontal tabs and the vertical passage of the connector block, said connector block being rotatable about the vertical pin; a horizontal pin inserted through the horizontal passage of the connector block; a left connector tab pivotally attached to one extending end of the horizontal pin; a right connector tab pivotally attached to the other extending end of the horizontal pin; a torque ring fixedly positioned between the left connector tab and the right connector tab with its centerline perpendicular to the centerline of the vertical pin; a vertical member having an upper end and its lower end pivotally attached to the mold board; a rod having one end attached to the upper end of the vertical member and its other end slidably and rotatably in serted through the torque ring; a positioning ring on the rod between the vertical member and the torque ring,

t 14 said positioning ring being adjacent to the torque ring and being too large to pass through the torque ring; a torque limiting ring fixedly on the rod between the left connector tab and right connector tab, said torque limiting ring being too large to pass through the torque ring; and stops extending from the torque limiting ring between the left connector tab and the right connector tab.

8. A slope grader for use with a road grader having a pivotally movable leveling blade, said slope grader, comprising, in combination, a mold board; means for mounting the mold board on the slope grader for pivotal motion in a horizontal plane; a leveling blade bracket mountable on the leveling blade of a road grader; two horizontal tabs spaced apart and extending from the leveling blade bracket toward the mold board; a connector block between the horizontal tabs, said connector block having a vertical passage through it and a horizontal passage through it more remote from the leveling blade bracket than the vertical passage; a vertical pin extending through the horizontal tabs and the vertical passage of the connector block, said connector block being rotatable about the vertical pin; a horizontal pin inserted through the horizontal passage of the connector block; a left connector tab pivotally attached to one extending end of the horizontal pin; a right connector tab pivotally attached to the other extending end of the horizontal pin; a torque ring fixedly positioned between the left connector tab and the right connector tab with its centerline perpendicular to the centerline of the vertical pin; a vertical member having an upper end and its lower end pivotally attached to the mold board; a rod having one end attached to the upper end of the vertical member and its other end slidably and rotatably inserted through the torque ring; a first positioning ring on the rod between the vertical member and the torque ring, said first positioning ring being adjacent to the torque ring and being too large to pass through the torque ring; and a second positioning ring on the rod between the left connector tab and right connector tab, said second positioning ring being too large to pass through the torque ring.

9. A slope grader for use with a road grader, said slope grader comprising, in combination, a pivot block; a mold board having a lengthwise axis, said mold board being pivotally attached to the pivot block and pivotable about a first axis substantially parallel to the lengthwise axis of the mold board; a heel member mounted on the road grader; means for attaching the pivot block to the heel member so that the pivot block is pivotable about a second axis perpendicular to said first axis; means for selectively pivoting said mold board about said second axis and a cam bar having its ends pivotally attached to the mold board and pivotable about a third axis parllel to the said first axis, said cam bar being slidably attached between its ends to the heel member and being curved so that the distance from the pivoted ends of the cam bar to the point of slidable attachment varies as the mold board is pivoted vertically about the pivot member.

10. A slope grader for use with a road grader, said slope grader comprising, in combination, a pivot block; a mold board having a lengthwise axis, said mold board being pivotally attached to the pivot block and pivotable about a first axis substantially parallel to the lengthwise axis of the mold board; a heel member mounted on the road grader; means for attaching the pivot block to the heel member so that the pivot block is pivotable about a second axis perpendicular to said first axis; a cam bar having its end pivotally attached to the mold board and pivotal about a third axis parallel to the said first axis; means for rotating the ends of said cam bar and said third axis about said second axis and means for causing rotation of said mold board about said first axis in response to such rotation.

11. A slope grader comprising, in combination, a mold board having a lengthwise axis, said mold board being pivotable about a first axis substantially parallel to 1 5 I 5 its lengthwise axis and about a second axis perpendicular 2,551,136 5/51 Kcltner 28791 to said first axis; and a positioning member attached to 2,847,772 8/58 McMullen 37155 the mold board and pivotal about a third axis parallel to 3,049,822 8/62 McMullen 37155 the said first axis; means for rotating the positioning 3,061,956 11/62 Brader 37155 member and said third axis about said second axis, and 5 3,122,850 3/64 Rockwell 37144 means for causing rotation of said mold board about said first axis in response to such rotation. ABRAHAM G. STONE, Primary Examiner.

References Cited by the Examiner BENJAMIN HERSH, WILLIAM A. SMITH III,

UNITED STATES PATENTS 10 Exammm 2,404,760 7/46 Washbond 37-144 

11. A SLOPE GRADE COMPRISING, IN COMBINATIN, A MOLD BOARD HAVING A LENGTHWISE AXIS, SAID MOLD BORD BEING PIVOTABLE ABOUT A FIRST AXIS SUBSTANTIALLYPARALLEL TO ITS LENGHTWISE AXIS AND ABOUT A SECOND AXIS PERPENDICULAR TO SID FIRST AXIS; AND A POSITIONING MEMBER ATTACHED TO THE MOLD BOARD AND PIVOTAL ABOUT A THIRD AXIS PARALLEL TO THE SAID FIRST AXIS; MEANS FOR ROTATING THE POSITIONING MEMBER AND SAID THIRD AXIS ABOUT SID SECOND AXIS, AND 